Recently, as wireless communication technology is advanced and equipment enabling the use of a wireless Internet service is widely distributed, an amount of used data increases. As the amount of used data increases, insufficiency of frequencies is coming to the fore as a great problem. To solve this problem, various technologies are being developed, and for example, may include high-order modulation technology, multiple-input multiple-output (MIMO) technology, signal separation technology using a polarized wave, etc.
However, in actually applying the technologies to a wireless communication system, there are problems such as a distance limitation between antennas, interference between signals, a complexity of implementation, etc. To solve the problems, proposed was a spatial modulation scheme that enhances frequency efficiency by using spatial information on a transmission antenna.
To describe an operation of a general spatial modulation scheme, before data is output to an antenna, the general spatial modulation scheme performs an operation that selects a specific antenna from among a plurality of antennas to effect switching. At this time, different delays can occur between switching signals used to determine whether to use the antennas. Due to such delays, discontinuity occurs between reception signals which are received and combined by a receiving end, and can cause serious signal distortion.